1. Field of the Invention
This invention relates to a copying apparatus, and more particularly to a copying apparatus in which the feeding time of a recording medium is controlled so that the relative position of an image to be formed on the recording medium and the recording medium is brought into a predetermined relationship.
2. Description of the Prior Art
In an electrophotographic copying apparatus, in order to register the leading end of transfer paper with the leading end of an image formed on a photosensitive medium by exposure and development, a predetermined rotated position of the photosensitive medium has been detected to operate a feed roller to feed the transfer paper to an image transfer station. However, this has offered a disadvantage that since the start of an optical system or an original carriage reciprocating to subject the photosensitive medium to exposure and scanning is not always constant, a latent image is not always formed at a predetermined location on the photosensitive medium and accordingly, the leading end of the image on the transfer paper is deviated. To overcome such a disadvantage, there is an apparatus in which a particular moved position of the optical system or the original carriage in their path is detected to operate a feed roller, but in such apparatus, the feeding time has been limited during the reciprocal movement of the optical system on the original carriage. Thus, this has not been applicable to copying machines in which image transfer takes place independently of the exposure and scanning.
Also, in copying machines wherein copying magnification is variable, the time relation between the timing for detecting a particular position of reciprocal movement and the feed timing differs in accordance with the magnification and the feed timing cannot indiscriminately be determined from the detection timing. This has also been the case with copying machines having a plurality of paper feed stations and having different lengths of feed paths for the respective paper feed stations.